Conductive yarn capable of withstanding dyeing, finishing and washing

ABSTRACT

The invention discloses a conductive yarn including a core yarn and at least one rolled metal wire with a corrosion or oxidation protection which is respectively and spirally wound around the core yarn. The conductive yarn according to the invention is capable of withstanding dyeing, finishing and washing, and has excellent stress resistance, better conductivity, yarn softness and flexibility such that it can be easily in a conventional textile fabrication process to become a conductive portion of textile article or be served as a conductive sewing thread. Moreover, according to the invention, the conductive yarn provides an intimate structure between the surface conductive material (rolled metal wires) and core material (core yarn). The structure can ensure the surface conductive material will not be fractured, and have a better and uniform conductivity.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This present invention relates to a conductive yarn, and more inparticular, to a conductive yarn capable of withstanding dyeing,finishing and washing.

2. Description of the Prior Art

It is well known that conductive yarns used in textile articles made invarious textile ways serves as circuitry, physiological detectors,electrodes, and other wearable electronic devices.

Just like manufacture of general textile articles, conductive yarns andwearable electronic devices made of such conductive yarns duringmanufacture thereof all are to be experienced dyeing and finishingprocedures (including yarn dyeing, fabric dyeing), and washingprocedures. Therefore, the conductive yarns are bound to be subjected toattack of acidic or alkaline dye bath, oxidizing agents, reducingagents, detergents, bleaches, and so on. In addition, during theprocedures and using, the conductive yarns always suffer from verycomplicated stresses and can be easily fractured. Finally, theconductive yarn loses the conductivity and quality.

One prior art regarding conductive yarns uses traditional copper wireswith excellent conductivity to be conductive yarns. However, copperwires are not suitable to be used as material of the conductive yarnsbecause the copper wire is too stiff to be a yarn for textilefabrication processes, and copper doesn't perform well in oxidation andcorrosion.

One other prior art regarding conductive yarns uses polymer filamentswith conductive particles doping or plating to form conductive yarns orfilaments. However, the doping or plating procedure takes higher cost,and the conductivity of the conductive yarns or filaments is much lowerthan that of the metal wire. In addition, the conductive polymer yarnsor filaments cannot be welded upon the traditional electronic devicewith traditional electronic skills.

One other prior art regarding conductive yarns uses enamel coveredcopper wires as raw material to form conductive yarns. However, duringmanufacture of a wearable electronic device utilizing such conductiveyarns, the enamel covered copper wires need to be peeled to bare thecopper wires therein, and the peeling procedure of the enamel coveredcopper wires needs to be performed by immersing the enamel coveredcopper wires in chemicals. Hence, the use of the enamel covered copperwires as raw material to form conductive yarns cannot still prevent fromcorrosion problem.

Referring to FIGS. 1A and 1B, those figures disclose another prior artregarding conductive yarns. FIG. 1A illustratively shows the structureof a conductive yarn 10 disclosed in specification of U.S. Pat. No.5,927,060. FIG. 1B is a sectional view of the conductive yarn 10 shownin FIG. 1A along the A-A line.

As shown in FIG. 1A, the conductive yarn 10 according to the prior artincludes a core yarn 12 constituted by a plurality of syntheticfilaments. The core yarn 12 is covered by at least two up to at mostfour metal filaments of stainless steel. The core yarn 12 of the exampleshown in FIG. 1A is covered by a metal filament 14 and another metalfilament 16 extending in a direction opposite that of the metal filament14.

However, as shown in FIG. 1A, the metal filaments (14, 16) do not fullycover the core yarn 12. During dyeing, finishing, washing and using ofthe conductive yarn 10, complicated mechanical stresses introduced byprocessing environment or using environment, is extremely likely toapply a higher thrust F to the metal filaments (14, 16), as shown inFIG. 1B. Moreover, as shown in FIG. 1B, the contact area of the metalfilaments (14, 16) with the contact surface of the core yarn 12 wound bythe metal filaments (14, 16) is very narrow and even nearly equal to aline. Because the shear stress is: τ=F/A where τ represents the shearstress, F represents the thrust (shear force), and A represents thecontact surface (shear surface), it is obvious that processingenvironment or using environment make the metal filaments (14, 16)extremely vulnerable to environment-induced shear stress such that themetal filaments (14, 16) are subsequently shifted from the originalwinding location on the contact surface of the core yarn 12, and evenpushed away from the core yarn 10, and finally broke. Therefore, theconductive yarn shown in FIG. 1A of the prior art in the long-termeasily loses its conductivity, and the metal filament fragments makewearers feel uncomfortable or itchy.

In addition, the metal filament (14, 16) is difficult to hold the coreyarn 10 because the contact surface between the wire and the core yarnis very small, and the elongation of metal filament (14, 16) isdifficult to match the elongation of the core yarn 10, hence thefabrication process can easily cause the protuberance of the metalfilament (14, 16).

SUMMARY OF THE INVENTION

Accordingly, one aspect of the invention is to provide a conductiveyarn. And in particular, the conductive yarn according to the inventionis capable of withstanding dyeing, finishing and washing, and hasexcellent stress resistance, better conductivity, softness andflexibility such that it can be easily used in a conventional textilefabrication process such as weaving, knitting and braiding to become aconductive portion of textile article or be served as a conductivesewing thread. Moreover, according to the invention, the conductive yarnprovides an intimate structure between the surface conductive material(rolled metal wires) and core material (core yarn). The intimatestructure can ensure the surface conductive material will not befractured, and have a better and uniform conductivity.

According to a preferred embodiment of the invention, the conductiveyarn structure includes a core yarn and at least one rolled metal wirewith corrosion or oxidation protection. The core yarn is constituted byat least one conductive core wire or filament with corrosion oroxidation protection, at least one short metal fiber yarns of withcorrosion or oxidation protection, at least one non-conductive corefilament or at least one non-conductive short fiber yarn. The at leastone rolled wire is respectively and spirally wound around the core yarn.

In one embodiment, materials used to fabricate the at least one rolledmetal wire with corrosion or oxidation protection, the at least oneconductive wire or filament with corrosion or oxidation protection andthe at least one short metal fiber yarns with corrosion or oxidationprotection respectively can be tin plating copper, gold plating copper,nickel plating copper, stainless steels (e.g., 316, 304, 420, containingcopper stainless steel, and containing silver stainless steel),titanium, titanium alloys (e.g., TA0, TA1, TA2, TA3, TA7, TA9, TA10,TC1, TC2, TC3, TC4(Ti6A14V)), nickel, silver, gold, nichrome, Ni—Cr—Mo—Walloys, tungsten, platinum, palladium, zirconium, zirconium alloys(e.g., alloy 702, alloy 704, alloy 705, alloy 706), tantalum, CuNialloys, CuNiSi alloys, CuNiZn alloys, CuNiSn alloys, CuCr alloys, CuAgalloys, CuW alloys, HASTELLOY type alloys (e.g., alloy C-22, alloy B-2,alloy C-22), NICKEL type alloys (e.g., Nickel 200, Nickel 201), MONELtype alloys (e.g., alloy 400, alloy R-405, alloy K-500), ICONEL typealloys (e.g., alloy 600, alloy 625), FERRALIUM type alloys (alloy 255),NITRONIC type alloys (e.g., NITRONIC 60, NITRONIC 50, NITRONIC 30),CARPENTER type alloys (alloy 20Cb-3), or other commercial ofcorrosion-resistant metals or alloys.

The material used to fabricate aforesaid the non-conductive corefilament and the non-conductive short fibers can be polyester,polyamide, polyacrylic, polyethylene, polypropylene, cellulose, protein,elastomeric, polytetrafluoroethylene, poly-p-phenylenebenzobisoxazole(PBO), polyetherketone, carbon, glass fiber, or other commercialmaterials to make non-conductive yarns.

The aspect of the present invention will no doubt become obvious tothose of ordinary skill in the art after reading the following detaileddescription of the preferred embodiment, which is illustrated in thefollowing figures and drawings.

BRIEF DESCRIPTION OF THE APPENDED DRAWINGS

FIG. 1A illustratively shows a structure of a conductive yarn 10according the prior art.

FIG. 1B is a sectional view of the conductive yarn shown in FIG. 1Aalong the A-A line.

FIG. 2A illustratively shows a structure of a conductive yarn 20according to a preferred embodiment of the invention.

FIG. 2B is a sectional view of the metal wire 24 without rolling shownin FIG. 2A along the C-C line and a sectional view of the rolled metalwire 24 shown in FIG. 2A along the C″-C″ line.

FIG. 2C is a sectional view of the conductive yarn shown in FIG. 2Aalong the B-B line.

FIG. 3A is an SEM photograph of the conductive yarn 20 according to thepreferred embodiment of the invention.

FIG. 3B is another SEM photograph showing the magnified view of a distalend of the conductive yarn 20 shown in FIG. 3A.

DETAILED DESCRIPTION OF THE INVENTION

Some preferred embodiments and practical applications of this presentinvention would be explained in the following paragraph, describing thecharacteristics, spirit and advantages of the invention.

Referring to FIGS. 2A, 2B and 2C, the FIG. 2A illustratively shows astructure of a conductive yarn 20 according to a preferred embodiment ofthe invention. FIG. 2B is a sectional view of the metal wire 24 withoutrolling shown in FIG. 2A along the C-C line and a sectional view of therolled metal wire 24 shown in FIG. 2A along the C″-C″ line. FIG. 2C is asectional view of the conductive yarn shown in FIG. 2A along the B-Bline.

As shown in FIG. 2A, the conductive yarn 20 according to the preferredembodiment of the invention includes a core yarn 22 and at least onerolled metal wire 24 with corrosion or oxidation protection.

In practical application, the core yarn 22 is constituted by at leastone conductive core wire or filament with corrosion or oxidationprotection, at least one short metal fiber yarns with corrosion oroxidation protection, at least one non-conductive core filament or atleast one non-conductive short fiber yarn. In the embodiment shown inFIG. 2A, the core yarn 22 is constituted by a plurality of corefilaments 222.

According to the preferred embodiment of the invention, at least onerolled metal wire 24 is respectively and spirally wound around the coreyarn 22. In the embodiment shown in FIG. 2A, the core yarn 22 is spiralwound around by the rolled metal wires 24. In practical application, thenumber of the rolled metal wires 24 spirally winding around the coreyarn 22 depends on practical requirement of the conductive yarn 20, suchas conductivity, softness, flexibility, mechanical properties, and soon.

Also shown in FIG. 2A, there is gap existing between neighboringencircles of the same rolled metal wire 24 wound around the core yarn22. In practical application, according to practical requirement of theconductive yarn 20, such as conductivity, softness, flexibility, andmechanical properties, etc., the neighboring encircles of the samerolled metal wire 24 wound around the core yarn 22 might be overlappedpartially.

In one embodiment, materials used to fabricate the at least one rolledmetal wire 24 with corrosion or oxidation protection, the at least oneconductive core wire or filament 22 with corrosion or oxidationprotection and the at least one short metal fiber core yarns 22 withcorrosion or oxidation protection respectively can be tin platingcopper, gold plating copper, nickel plating copper, stainless steels(e.g., 316, 304, 420, containing copper stainless steel, and containingsilver stainless steel), titanium, titanium alloys (e.g., TA0, TA1, TA2,TA3, TA7, TA9, TA10, TC1, TC2, TC3, TC4(Ti6A14V)), nickel, silver, gold,nichrome, Ni—Cr—Mo—W alloys, tungsten, platinum, palladium, zirconium,zirconium alloys (e.g., alloy 702, alloy 704, alloy 705, alloy 706),tantalum, CuNi alloys, CuNiSi alloys, CuNiZn alloys, CuNiSn alloys, CuCralloys, CuAg alloys, CuW alloys, HASTELLOY type alloys (e.g., alloyC-22, alloy B-2, alloy C-22), NICKEL type alloys (e.g., Nickel 200,Nickel 201), MONEL type alloys (e.g., alloy 400, alloy R-405, alloyK-500), ICONEL type alloys (e.g., alloy 600, alloy 625), FERRALIUM typealloys (alloy 255), NITRONIC type alloys (e.g., NITRONIC 60, NITRONIC50, NITRONIC 30), CARPENTER type alloys (alloy 20Cb-3), or othercommercial corrosion-resistant metals or alloys.

In one embodiment, material used to fabricate aforesaid thenon-conductive core filament and the non-conductive short fibers can bepolyester, polyamide, polyacrylic, polyethylene, polypropylene,cellulose, protein, elastomeric, polytetrafluoroethylene,poly-p-phenylenebenzobisoxazole (PBO), polyetherketone, carbon, glassfiber, or other commercial materials to make non-conductive yarns.

According to the preferred embodiment of the invention, the structure ofconductive yarn 20 can designed according to functional requirement suchyield tension, yield torsion, fire resistance, conductivity and so on.

As shown in FIG. 2B, the metal wire 24 without rolling has a length t, adiameter d, and a volume equal to π (d/2)²xt, and has the contact areawith the core yarn 22 nearly equal to a line. Also shown in FIG. 2B, therolled metal wire 24, similarly with a length t, has a thickness d/5 anda volume equal to that of the metal wire 24 without rolling, and has thecontact area with the core yarn 22 equal to 4dxt.

Obviously, different from the prior art, the invention is to roll themetal wire to get the rolled metal wire having identical volume to thatof the metal wire without rolling and but the larger contact area withthe core yarn where the rolled metal wire is spirally wound around thecore yarn. By tightly winding the rolled metal wire 24 around the coreyarn 22, the conductive yarn 20 according to the invention hasconsiderable compliance between the core yarn 22 and the rolled metalwire 24. More importantly, during the dying, finishing, washing andusing of the conductive yarn 20, it is very likely to apply a higherthrust F to the rolled metal wire 24, as shown in FIG. 2C. And as shownin FIG. 2C, the rolled metal wire 24 is completely cover the core yarn22 and has the larger contact area with the core yarn 22. It isobviously that the environment-induced shear stress exerting on theenvironment of the rolled metal wire 24 is much higher than theenvironment-induced shear stress exerting on the metal wire withoutrolling of the prior art, such that the rolled metal wire 24 is verydifficult to be removed from the original position, or cannot be pushedaway from the core yarn 22, or cannot be fractured.

In addition, in FIG. 2B, the cover width 4 d of the rolled metal wirecan be easily adjusted by rolling force according to the demand ofsoftness of the conductive yarn.

The smaller the cover width is, the softer the conductive yarn is.However, the smaller the cover width is, the weaker the stressresistance is. The conductive yarn 20 according to the invention hasexcellent yarn softness and flexibility such that it is available to beeasily woven in a conventional textile way into a conductive portion ofa textile article, or to be served as a conductive sewing thread. Thefabrication process would not cause any protuberance of the rolled metalwire 24 because the rolled metal wire 24 with large cover width can holdthe core yarn 22 much tied.

In addition, in FIG. 2A, the layer of the rolled metal wire is at leastone layer. The number of the layer can be increased by increasing numberof the metal wire during the rolling procedure to increase theconductivity. Furthermore, the excellent stress resistance also ensuresa uniform conductivity.

During dyeing, finishing, washing and using of the conductive yarn 20,it is obviously that the conductive yarn 20 is capable of resistingcorrosion resulting from for example acidic or alkaline agent, oxidant,reducing agent, detergent, bleach and so on, and maintains its originalconductivity. Furthermore, the conductive yarn 20 according to theinvention has excellent yarn softness and flexibility such that it canbe easily used in a conventional textile fabrication process such asweaving, knitting and braiding to become a conductive portion of textilearticle or be served as a conductive sewing thread.

Also shown in FIG. 2A, according to another preferred embodiment of theinvention, the at least one rolled metal wire is also pressed in apattern during being rolled by a pattern carved roller. In this way, thesurface of the at least one rolled metal wire 24 has the correspondingpattern 26. The surface of the rolled metal wire 24 can providedifferent light refractions to produce different visual effects by useof different patterns 26. In addition, the rolled metal wire 24 withpattern of the invention can also provide anti-counterfeiting featuresby use specific patterns 26.

Referring to FIG. 3A and FIG. 3B, FIG. 3A is an SEM photograph of theconductive yarn 20 according to the preferred embodiment of theinvention. FIG. 3B is another SEM photograph showing the magnified viewof a distal end of the conductive yarn 20 shown in FIG. 3A.

As shown in FIG. 3A, the rolled metal wire 24 completely covers the coreyarn 22 constituted by a plurality of filament, and has large contactarea with the core yarn 22. As shown in FIG. 3B, the conductive yarn 20has considerable compliance between the core yarn 22 and the rolledmetal wire 24. That is, the conductive yarn 20 according to theinvention provides an intimate structure between the surface conductivematerial (rolled metal wires) and core material (core yarn). Theintimate structure can ensure the surface conductive material will notbe fractured, and have a better and uniform conductivity.

With the example and explanations above, the features and spirits of theinvention will be hopefully well described. Those skilled in the artwill readily observe that numerous modifications and alterations of thedevice may be made while retaining the teaching of the invention.Accordingly, the above disclosure should be construed as limited only bythe metes and bounds of the appended claims.

1. A conductive yarn, comprising: a core yarn selected from the groupconsisting of at least one conductive core wire or filament withcorrosion or oxidation protection, at least one short metal fiber yarnswith corrosion or oxidation protection, at least one non-conductive corefilament or at least one non-conductive short fiber yarn; and at leastone rolled metal wire with corrosion or oxidation protection spirallywinding around the core yarn; whereby said conductive yarn is capable ofwithstanding dyeing, finishing and washing.
 2. The conductive yarn ofclaim 1, wherein said at least one conductive core wire or filament withcorrosion or oxidation protection, said at least one short metal fiberyarns with corrosion or oxidation protection and said at least onerolled metal wire with corrosion or oxidation protection respectivelyare one selected from the group consisting of tin plating copper, goldplating copper, nickel plating copper, stainless steels, titanium,titanium alloys, nickel, silver, gold, nichrome, Ni—Cr—Mo—W alloys,tungsten, platinum, palladium, zirconium, zirconium alloys, tantalum,CuNi alloys, CuNiSi alloys, CuNiZn alloys, CuNiSn alloys, CuCr alloys,CuAg alloys, CuW alloys, HASTELLOY type alloys, NICKEL type alloys,MONEL type alloys, ICONEL type alloys, FERRALIUM type alloys, NITRONICtype alloys, and CARPENTER type alloys.
 3. The conductive yarn of claim1, wherein the at least one rolled metal wire is also pressed in apattern during being rolled by a pattern caved roller.
 4. The conductiveyarn of claim 1, wherein the at least one non-conductive core filamentand the at least one non-conductive short fiber yarn are made of amaterial selected from the group consisting of polyester, polyamide,polyacrylic, polyethylene, polypropylene, cellulose, protein,elastomeric, polytetrafluoroethylene, poly-p-phenylenebenzobisoxazole(PBO), polyetherketone, carbon, and glass fiber.